This invention relates generally to loose leaf binders and particularly to ring mechanisms employed therewith.
Loose leaf binders employing prior art ring mechanisms and particularly toggle ring mechanisms employing rings of generally circular shape, when filled to capacity with loose leaf sheets, often cause the sheets to wedge between the ring mechanism and the inside surface of the binder covers as they are opened and closed whereby there is a tendency for sheets to be torn. In addition, such a condition inhibits full closure of the binder covers.
One remedy for this paper jamming situation has been the utilization of sheet lifters in the form of plastic panels fitted onto the rings between the loose leaf sheets and the covers. Although such lifter panels help prevent jamming of the sheets, these lifters take up space which could otherwise be used for sheets and add to the cost of the binder.
Various ring configurations have been proposed as solutions to such paper jamming problems, but often the ring shapes present complex paths having one or more sharp corners along which the loose leaf sheets must be swung when leafing through the pages in the binder. In addition, specially designed rings usually require use of particular binder structures to accommodate each distinctive ring configuration.
Accordingly, it is a principal object of the present invention to provide a loose leaf binder which overcomes the deficiencies of the prior art.
It is another object of the present invention to provide a loose leaf binder wherein the risk of loose leaf sheets being caught between the ring mechanism and the covers thereof is minimized.
It is another object of the present invention to provide a loose leaf binder having non-circular ring structures which provide non-retrogressive paths of movement for loose leaf sheets held thereby.